Funds are requested to help support a Gordon Research Conference, Mechanisms of Membrane Transport, to be held from June 15-20 in 2003 at Holderness School, Plymouth, New Hampshire. This meeting continues a very successful series, held every two years, on topical subjects of high interest to the membrane transport field. This year we will highlight the tremendous advances in understanding that have been enabled by the recent availability of high-resolution structures of membrane channels and transporters. These developments are of great biological significance, and as outlined herein, are both timely and medically relevant. The subjects are important to a wide range of clinical disciplines, and have particular applicability to kidney and gastrointestinal function and neuronal excitability. The meeting will also incorporate advances in the physical basis for membrane protein structure, molecular dynamics modeling of solute movements through channels, and single-molecule approaches to elucidation of mechanism. They will naturally bring together scientists from a wide range of disciplines and promote fruitful interactions that otherwise would probably never occur. Relevant disciplines include biochemistry, biophysics, physiology, cell biology, molecular biology, genetics, pharmacology, and internal medicine. The program is organized to focus on selected transporter families for which crystal structures are available or will soon become available. The meeting includes 31 regular talks and 2 special talks, organized in 9 sessions. The speakers will plan their talks for a very mixed audience, and the attendance of students, fellows, and clinicians will be encouraged. The poster sessions will be strongly promoted, and further emphasized by the selection of four 'short selected talks'. Young investigators will be especially encouraged to attend, present their work, and participate in discussions.